In the past, at least five states expressed interest in weapons designed to disperse radioactive material without a nuclear detonation. Four states actively pursued them, and three—Iraq, the Soviet Union, and the United States—tested them on multiple occasions before ultimately choosing not to deploy them. The largely obscure history of the development of radiological weaponry helps to explain its appeal, especially in the context of rising international hostilities, a breakdown in nuclear arms control, and a loss of faith in the credibility of security assurances.

--SSP Stanton Nuclear Fellow Sarah Bidgood in Foreign Affairs (with William C. Potter and Hanna Notte)